Two devices can communicate network data with each other using a link that couples the two devices, where the link can be a wired or wireless connection. This link can transport the network data while the link is in the up state. In contrast, the link cannot transport the network data if the link is in a down state. A down state can result from a reset of the port of either device coupled to the link, a reboot of one of the devices, or the port being forced down administratively using configuration commands. A problem can arise if the link transitions from the up state to the down and back again occur frequently. For example, the link can repeatedly transition from the up state to the down state and back to the up state within a short period of time. This repeated set of link transitions from an up to down to up state is known as link flapping.
There can be two kinds link flapping: a fast link flap in which there are multiple link flaps in a short period of time and a slow link flap in which there are multiple link flaps over a longer period of time. Each time the link transitions from the up state to the down state, network-based services can be disrupted and there is additional work that the service performs if the link comes back up. This disruption can lead to poor performance for the service. A fast link flap is detected by counting the number of link flaps within a short time period and determining if this number of link flaps is greater than a predetermined threshold. However, a slow link flap can still cause network disruption in network service to the point that it would be useful to detect a slow link flap event and allow a system administrator to take corrective action.